JP4811510B2 - Electrophoretic display device and driving method thereof - Google Patents

Description

  The present invention relates to an electrophoretic display device and a driving method thereof.

  Electrophoretic display elements have begun to be used in fields such as electronic books, mobile phones, electronic shelf labels, and watches. The electrophoretic display element can obtain reflectivity, contrast, and viewing angle close to those of paper, and display that is easy on the eyes. Further, the electrophoretic display element has a memory property, and power is consumed only when the display is rewritten. Therefore, in the electrophoretic display device, power is not required once an image is displayed. For this reason, it is a display element with low power consumption. Further, the structure of the electrophoretic display element is simpler than the structure of a liquid crystal display element or an organic EL display element. For this reason, flexible display elements are expected.

  As an electrophoretic display element, for example, a microcapsule structure electrophoresis system disclosed in Patent Document 1 is known. In the electrophoretic display element disclosed in Patent Document 1, a microcapsule in which a solvent, charged white fine particles, and reverse charged black fine particles charged in reverse polarity with respect to the charged white fine particles are enclosed is used. This electrophoretic display element has a configuration in which the microcapsules are sandwiched between electrodes. Patent Document 1 discloses a technique in which fine particles in the microcapsule are migrated by an electric field generated by the electrodes, and black or white is displayed on the display element.

Special table 2007-507737

  When charged fine particles and reversely charged fine particles are used as in the technique of the electrophoretic display element disclosed in Patent Document 1, an attractive force acts between these fine particles. For this reason, the charged fine particles and the reverse charged fine particles are liable to aggregate. Such agglomeration of fine particles may cause a color mixture of the color of the charged fine particles and the color of the oppositely charged fine particles. This color mixture is not preferable because it reduces the contrast of the image displayed on the electrophoretic display element. In addition, when the electric field applied to the electrophoretic display element for black display or white display is changed, the behavior of the aggregated fine particles may cause a rapid change in display reflectance. This abrupt change in display reflectance may cause the viewer to feel a flicker that is uncomfortable.

  Accordingly, an object of the present invention is to provide an electrophoretic display device that displays a good image quality, and a driving method thereof, by improving the inconvenience of display of an electrophoretic display element caused by aggregation of charged fine particles and reverse charged fine particles. To do.

In order to achieve the above object, one embodiment of an electrophoretic display device of the present invention includes a first substrate, a second substrate facing the first substrate by forming a gap having a constant interval, and closed in the gap . Forming at least one pixel space, which is a space, a partition wall portion that forms a boundary of the pixel space together with the first substrate and the second substrate, and is formed on the first substrate in the pixel space and positively charged particles having a first electrode which is a second electrode formed on the second substrate in the pixel space, a positive charge that is sealed in the pixel space, wherein Negatively charged fine particles having a negative charge enclosed in a pixel space, a thin film transistor having a source electrode connected to the first electrode, and a scanning signal voltage for selectively turning on the thin film transistor, the thin film transistor Used for the gate electrode of A display line including a scanning line to which the positively charged fine particles and the negatively charged fine particles migrate and a signal line for supplying the data signal voltage to the drain electrode of the thin film transistor, and applying the scanning signal voltage to the scanning line A scanning signal voltage applying unit, and a data signal voltage applying unit that applies the data signal voltage to the signal line, wherein the data signal voltage includes a write signal voltage for displaying an image on the display unit, A data signal voltage application unit including a post-write signal voltage whose voltage changes stepwise from a write signal voltage to a holding signal voltage for maintaining the display state of the display unit, and applying the scanning signal voltage The unit has a potential different from the holding signal voltage during a holding operation for maintaining the display state of the display unit after the data signal voltage has shifted to the holding signal voltage. A scanning signal voltage to the thin film transistors because set to OFF state and applying to the scanning lines.

In order to achieve the above object, according to one embodiment of the driving method of the electrophoretic display device of the present invention, an image is displayed by electrophoresing charged particles in a dispersion material enclosed in a pixel space which is a closed space. An electrophoretic display device driving method for driving a display unit, comprising: applying a common voltage to a common electrode in the pixel space; and applying the common voltage to the pixel electrode in the pixel space. applying a write signal voltage for displaying an image, during a period in which to apply the common voltage, the holding signal for maintaining the display state of the display unit from said write signal voltage to the pixel electrode a step of the stepwise voltage to a voltage is applied to that after writing a signal voltage change, after the voltage of the pixel electrode is shifted to the holding signal voltages, different electric potentials and the holding signal voltage previously set Applying a scanning signal voltage to the thin film transistors in the OFF state to the scanning line, characterized in that it comprises a.

  ADVANTAGE OF THE INVENTION According to this invention, the electrophoretic display apparatus which displays the favorable image quality which improved the display inconvenience of the electrophoretic display element which generate | occur | produces by aggregation of a charged fine particle and a reverse charged fine particle, and its drive method can be provided.

FIG. 6 is a diagram schematically illustrating an example of a configuration of an electrophoretic display device according to one embodiment of the present invention. 1 is a plan view illustrating an outline of an example of a structure of an electrophoretic display device according to one embodiment of the present invention. 1 is a cross-sectional view illustrating an outline of an example of a structure of an electrophoretic display device according to one embodiment of the present invention. 4A and 4B illustrate a display principle of an electrophoretic display device according to one embodiment of the present invention. 4 is a timing chart for driving a TFT of the electrophoretic display device according to one embodiment of the present invention. The schematic diagram which shows cancellation | dissolution of aggregation of the black positively charged fine particle and the white negatively charged fine particle by the pre-pulse operation. The figure explaining the change of blackness by the behavior of fine particles before and after pixel voltage application stop. 10 is a drive timing chart of an electrophoretic display device according to a modification of one embodiment of the present invention.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing the configuration of the electrophoretic display device according to this embodiment. As shown in FIG. 1, the electrophoretic display device includes a display panel 100, a scan driver 420, a signal driver 440, a control unit 460, and a power supply adjustment unit 480. The display panel 100 is a part that displays an image based on the image data D. The display panel 100 includes a display element having a configuration in which an electrophoretic layer is sandwiched between a pixel side substrate 110 and a COM substrate 200.

  The pixel side substrate 110 has a plurality of scanning lines 140 (G (j) (j = 1, 2,..., N)) and a plurality of signal lines 150 (S (i) (i = 1, 2,..., M). )) And are arranged so as to cross each other. A pixel electrode 120 is disposed at a position corresponding to each intersection of the scanning line 140 and the signal line 150. The pixel electrode 120 is electrically connected to the scanning line 140 (G (j)) and the signal line 150 (S (i)) via a thin film transistor (TFT) 130. Accordingly, m pixel electrodes 120 are connected to each scanning line, and n pixel electrodes 120 are connected to each signal line. In FIG. 1, the range of n = 4 and m = 4 is schematically shown for simplicity. The scanning line 140 is connected to the scanning driver 420, and the signal line 150 is connected to the signal driver 440. The scanning driver 420 and the signal driver 440 are each connected to the control unit 460. Further, a power supply adjustment unit 480 is connected to the COM substrate 200. Further, the power supply adjustment unit 480 is also connected to the scanning driver 420 and the signal driver 440.

  An example of the structure of the display panel 100 according to the present embodiment will be further described with reference to FIGS. 2 is a plan view of a display portion of the display panel 100, and FIG. 3 is a cross-sectional view taken along line A-A 'in FIG. For example, a pixel electrode 120 made of an indium tin oxide (ITO) film or the like is formed on the pixel side substrate 110 such as a glass substrate. As shown in FIGS. 2 and 3, the pixel electrode 120 is formed so that one pattern corresponds to one pixel. Each pixel electrode 120 is connected to the source electrode of the TFT 130 as a switching element. The scanning line 140 is connected to the gate electrode of the TFT 130, and the signal line 150 is connected to the drain electrode. As described above, the scanning line 140 and the signal line 150 intersect each other. Although not shown in FIGS. 2 and 3, auxiliary capacitance electrodes are formed between the pixel side substrate 110 and the respective pixel electrodes 120. Each auxiliary capacitance electrode is connected to an auxiliary capacitance line. A microrib 160 is formed on a part of the scanning line 140, the signal line 150, the auxiliary capacitance line, the TFT 130, and the pixel electrode 120 so as to surround each pixel electrode 120 and expose the upper surface of the pixel electrode 120. Yes.

  A COM substrate 200 is placed on the upper bottom of the microrib 160. Here, the COM substrate 200 is obtained by forming a common electrode 220 on a transparent substrate 210 having transparency such as a glass substrate. The common electrode 220 is a transparent conductive film such as an ITO film. The common electrode 220 is connected to the power supply adjustment unit 480. As shown in FIG. 3, in the pixel section surrounded by the pixel side substrate 110, the COM substrate 200, and the microrib 160, black positively charged fine particles 320 suspended in a solvent 310 and white negatively charged particles are provided. Fine particles 330 are enclosed.

  Thus, for example, the pixel-side substrate 110 functions as a first substrate, for example, the pixel electrode 120 functions as a first electrode, for example, the microrib 160 functions as a partition wall, and the transparent substrate 210 functions as a second substrate, for example. For example, the common electrode 220 functions as a second electrode, for example, the solvent 310 functions as a dispersion material, for example, the black positively charged fine particles 320 function as positively charged fine particles, for example, white negatively charged fine particles 330. Functions as negatively charged fine particles, for example, the scanning driver 420 and the signal driver 440 function as a signal voltage application unit, and the power supply adjustment unit 480 functions as a common voltage application unit, for example.

  Next, the operation of the electrophoretic display device according to this embodiment will be described. The scan driver 420 illustrated in FIG. 1 sequentially applies scan signals to the scan lines 140 (G (j)) of the display panel 100 using the power supplied from the power supply adjustment unit 480 under the control of the control unit 460. . When the ON voltage of the scanning signal is applied to the scanning line 140, the TFT 130 connected to the scanning line 140 is turned on. At this time, the signal driver 440 applies a data signal to the signal line 150 (S (i)) using the power supplied from the power supply adjustment unit 480 under the control of the control unit 460. The data signal applied to the signal line 150 (S (i)) is applied to the corresponding pixel electrode 120 via the TFT 130 turned on by the scanning signal. A pixel voltage is generated by this data signal.

  In this way, a scanning signal is sequentially applied to each scanning line 140, and at the same time, a data signal is applied to the signal line 150 to which the pixel electrode 120 to which a pixel voltage is to be applied is connected. As a result, a pixel voltage can be applied to a desired pixel electrode 120 among all the pixel electrodes. On the other hand, the common electrode 220 is maintained at a constant potential, for example, 0 V, by the power supply adjustment unit 480. Further, the auxiliary capacitance electrode below the pixel electrode 120 is also maintained at the same potential as the common electrode 220 by the power supply adjustment unit 480. Accordingly, a storage capacitor is formed by the pixel electrode 120 and the auxiliary capacitor electrode. The storage capacitor is for holding a pixel voltage based on a data signal supplied to the pixel electrode 120.

  The display principle of the electrophoretic display device according to this embodiment is shown in FIG. When a pixel voltage is applied through the pixel electrode 120, an electric field is generated between the pixel electrode 120 and the common electrode 220. Then, according to the generated electric field, the black positively charged fine particles 320 move in the solvent 310 toward the negative electrode, and the white negatively charged fine particles 330 move toward the positive electrode, respectively. As a result, when the electrophoretic display element is observed from the COM substrate 200 side in the direction of the black arrow in FIG. 4, since the COM substrate 200 is transparent, a pixel in which black positively charged fine particles 320 are collected on the common electrode 220, that is, a pixel. A pixel to which a positive voltage is applied to the electrode 120 appears black (the middle pixel in FIG. 4), and conversely, a pixel in which white negatively charged fine particles 330 are collected on the common electrode 220, that is, a negative voltage to the pixel electrode 120. The pixel to which is applied appears white (left and right pixels in FIG. 4). That is, black or white can be displayed for each pixel. Thus, by arranging the pixels to be displayed in black or white in a matrix, a desired image composed of two colors can be displayed by combining black or white displayed by each pixel.

  Here, a driving method of the electrophoretic display device according to the present embodiment will be described. The driving operation of the electrophoretic display device is divided into four steps. The first is a pre-pulse operation for eliminating the aggregation of black positively charged fine particles 320 and white negatively charged fine particles 330. The second is a writing operation for displaying a desired image on the electrophoretic display device. The third is a write end operation for ending the write operation. The fourth is a holding operation for maintaining the display of a desired image written in the electrophoretic display device by the writing operation. FIG. 5 shows a driving timing chart of the TFT 130 of the electrophoretic display device. In FIG. 5, the upper stage shows the potential of the jth scanning line 140G (j), and the lower stage shows the potential of the ith signal line 150S (i).

  First, a prepulse operation is performed. In the pre-pulse operation, the black positively charged fine particles 320 and the white negatively charged fine particles 330 are prevented from moving between the pixel electrode 120 and the common electrode 220 while being aggregated. In this pre-pulse operation, a pixel voltage is applied to all pixels. Therefore, it is not necessary to apply the pixel voltage for each scanning line, and the pixel voltage is applied to all the pixels at once. Therefore, in order to turn on all the TFTs 130, the scanning driver 420 switches the scanning signal applied to all the scanning lines 140 from the gate off level Vgl to the gate on level Vgh. While the scanning signal applied to the scanning line 140 is at the gate-on level Vgh, the signal driver 440 applies a predetermined voltage + V pulse and a voltage −V pulse to all the signal lines 150 with reference to the common voltage. Are alternately applied a predetermined number of times.

  By this pre-pulse operation, a force is applied to the black positively charged fine particles 320 and the white negatively charged fine particles 330 so as to reciprocate in the opposite directions. As a result, as shown in the schematic diagram on the left of FIG. 6, the black positively charged fine particles 320 and the white negatively charged fine particles 330 that have aggregated before the pre-pulse operation are disassembled apart as shown in the schematic diagram on the right of FIG. .

  Next, a write operation is performed. Here, the scanning driver 420 sequentially switches the scanning signal applied to the scanning line 140 (G (j)) from the gate-off level Vgl to the gate-on level Vgh. The time during which Vgh is applied to each row (each scanning line 140 (G (j))) is one horizontal period which is a period for applying a data signal for one row (one scanning line). When the potential of the scanning line 140G (j) becomes Vgh, the TFT 130 connected to the scanning line 140G (j) is turned on. At this time, the signal driver 440 applies a data signal to the signal line 150 (S (i)). Then, the data signal applied to the signal line 150 (S (i)) is applied to the corresponding pixel electrode 120 via the TFT 130 which is turned on by the scanning signal. In this manner, by applying a scanning signal to each scanning line 140 in order and simultaneously applying a data signal to the signal line 150 to which a pixel voltage is to be applied, the pixel voltage is applied to the desired pixel electrode 120 among all the pixel electrodes. Can be applied. On the other hand, the common electrode 220 is maintained at a constant potential. Due to the potential difference between the pixel electrode 120 and the common electrode 220, the black positively charged fine particles 320 and the white negatively charged fine particles 330 migrate. However, it is conceivable that the black positively charged fine particles 320 and the white negatively charged fine particles 330 are not sufficiently migrated by applying the pixel voltage once. Therefore, it is preferable to repeat the application of the pixel voltage a predetermined number of times every frame time. At this time, the storage capacitor formed by the pixel electrode 120 and the auxiliary capacitor electrode assists in maintaining the potential of the pixel electrode 120 while the scanning signal and the data signal are not applied. As the black positively charged fine particles 320 and the white negatively charged fine particles 330 move, the charge accumulated in the storage capacitor is consumed. Therefore, it is desirable to make the auxiliary capacitance electrode as large as possible.

  By the way, even if the pre-pulse operation is performed before the write operation, there is a possibility that the fine particles remain undissolved or re-aggregate during the write operation. In this case, at the time of the writing operation, the electrophoresis may be performed while the fine particles are aggregated. A schematic diagram in such a case is shown in FIG. When the observer observes the electrophoretic display device from the side of the COM substrate 200 in the direction of the black arrow in FIG. Arranged in the pixel space. As a result, black fine particles are observed and appear black in the pixel. However, when the application of the pixel voltage is stopped, the agglomerated particles may wrap around each other as shown in the right of FIG. In this case, a slight white fine particle appears to be mixed in the black fine particle from the observer. For this reason, when the application of the pixel voltage is stopped, the black color appears to the observer to be reduced. When such a change in blackness occurs abruptly, the observer feels flickering with a strange feeling on the display.

Therefore, in the present embodiment, as shown in FIG. 5 , after the end of the write operation, the pixel voltage is gradually decreased as the write end operation. That is, the potential of the data signal applied by the signal line 150 (S (i)) while the potential of the scanning line 140G (j) is Vgh is gradually changed, for example, every one frame time. The potential of the electrode 200), for example, close to 0V. As a result, the speed of the color change generated when the fine particles aggregated as described above wrap around each other decreases. Due to the decrease in the color change speed due to the writing end operation, the electrophoretic display device according to the present embodiment enables display that makes it difficult for an observer to feel flickering that is uncomfortable.

Finally, in the holding operation , application of the scanning signal and the data signal is stopped. Even if the application of the scanning signal and the data signal is stopped, the fine particles remain on the electrode due to the attractive force acting between the fine particles and the electrode such as van der Waals force, and the display of the written image is maintained.

  Thus, for example, the pre-pulse operation is performed by applying the signal voltage before writing, for example, the writing operation is performed by applying the writing signal voltage, and for example, the writing end operation is performed by applying the signal voltage after writing.

  In the description of the present embodiment, the case where black particles charged positively and white particles charged negatively are enclosed in each pixel section has been described as an example. However, the charged state of the black fine particles and the white fine particles may be reversed. The color of the fine particles may be other colors.

  Further, the pixel-side substrate of the present embodiment may be a substrate having no transparency such as a glass substrate, a metal substrate, a plastic substrate, or a film substrate. Further, the TFT may be a low-temperature p-Si TFT, a μc-Si TFT, an oxide (ZnO, InGaZnO, etc.) TFT, an organic TFT, or the like. The pixel electrode 120 has been described as an ITO film, for example. However, unlike the case of a liquid crystal display panel or the like, the display in the case of an electrophoretic display panel is a reflection method, and thus the pixel electrode 120 does not need to be transparent. Accordingly, the pixel electrode 120 may be an opaque electrode.

  Further, in order to realize the memory characteristic of the electrophoretic display element, that is, to maintain the display without consuming power after the image is once displayed on the display element, the leakage current of the TFT 130 is reduced as much as possible. It needs to be small. Therefore, a dual gate structure in which the resistance value is increased by connecting two TFTs as switching elements in series may be used.

  In the present embodiment, the black positively charged fine particles 320 and the white negatively charged fine particles 330 that have been aggregated by the pre-pulse operation are unraveled so that the contrast of the image displayed on the electrophoretic display device caused by the mixed color of black and white is increased. Decline can be prevented. In addition, if the prepulse operation is performed on all pixels at the same time, the time can be shortened compared with the case where the prepulse operation is performed for each scanning line.

  In the present embodiment, after the write operation is completed, the pixel voltage is gradually decreased as the write end operation. By this writing end operation, the speed of the color change caused by the fine particles aggregated after the end of the writing operation wrap around each other is reduced. As a result, the electrophoretic display device can perform a display that makes it difficult for an observer to feel flickering that is uncomfortable.

  Next, a modification of this embodiment will be described. Here, in the description of this modification, the description will be limited to the differences from the first embodiment. In the first embodiment, the case of the active matrix driving method using the TFT 130 has been described as an example, but a segment driving method may be used. In this case, as in the first embodiment, each segment of the electrophoretic display device has a section surrounded by the pixel electrode 120 and the common electrode 220 connected to the driver, and the microrib 160. In this compartment, a solvent 310, black positively charged fine particles 320, and white negatively charged fine particles 330 are enclosed. In the case of a segment drive type electrophoretic display device having such a configuration, a voltage as shown in FIG. 8 is applied to the pixel electrode of each segment.

  That is, first, as a pre-pulse operation, a predetermined voltage + V pulse and a voltage −V pulse are alternately applied to each segment a predetermined number of times based on the common voltage. Next, as a write operation, a voltage for writing is applied to each segment. Then, as the write end operation, the voltage applied to the segment that has performed the write operation is gradually reduced. At this time, the voltage may be decreased stepwise as indicated by the solid line in FIG. 8, or may be gradually decreased as indicated by the dotted line. Finally, as a holding operation, the voltage applied to the segment is maintained at 0 V, for example.

  Also in this modification, the operation of each part and the behavior of the charged fine particles are the same as those in the first embodiment. Therefore, the same effect as that of the first embodiment can be obtained.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of problems to be solved by the invention can be solved and the effect of the invention can be obtained. The configuration in which this component is deleted can also be extracted as an invention.

  DESCRIPTION OF SYMBOLS 100 ... Display panel, 110 ... Pixel side substrate, 120 ... Pixel electrode, 130 ... Thin-film transistor (TFT), 140 ... Scanning line, 150 ... Signal line, 160 ... Microrib, 200 ... COM substrate, 210 ... Transparent substrate, 220 ... Common electrode, 310 ... solvent, 320 ... black positively charged fine particles, 330 ... white negatively charged fine particles, 420 ... scan driver, 440 ... signal driver, 460 ... control unit, 480 ... power supply adjusting unit.

Claims (14)

A first substrate;
A second substrate facing the first substrate by forming a gap at a predetermined interval;
A partition portion that forms at least one pixel space, which is a space closed in the gap, and forms a boundary of the pixel space together with the first substrate and the second substrate;
A first electrode formed on the first substrate in the pixel space;
A second electrode formed on the second substrate in the pixel space;
Positively charged fine particles having a positive charge enclosed in the pixel space ;
Negatively charged fine particles having a negative charge enclosed in the pixel space ;
A thin film transistor having a source electrode connected to the first electrode;
A scanning line for supplying a scanning signal voltage for selectively turning on the thin film transistor to a gate electrode of the thin film transistor;
A signal line for supplying a data signal voltage for migrating the positively charged fine particles and the negatively charged fine particles to the drain electrode of the thin film transistor;
A display unit including:
A scanning signal voltage application unit for applying the scanning signal voltage to the scanning line;
A data signal voltage application unit for applying the data signal voltage to the signal line, wherein the data signal voltage is:
A write signal voltage for displaying an image on the display unit;
A post-write signal voltage in which the voltage gradually changes from the write signal voltage to a holding signal voltage for maintaining the display state of the display unit;
Including a data signal voltage application unit,
Comprising
The scanning signal voltage application unit is set in advance to a potential different from the holding signal voltage during a holding operation for maintaining the display state of the display unit after the data signal voltage has shifted to the holding signal voltage. An electrophoretic display device , wherein a scanning signal voltage for turning off the thin film transistor is applied to the scanning line . The electrophoretic display device according to claim 1, wherein the data signal voltage application unit applies the post-write signal voltage over a plurality of frame periods. The electrophoretic display device according to claim 1, further comprising a common voltage applying unit that applies a common voltage to the second electrode. 4. The electrophoretic display device according to claim 3, wherein the data signal voltage includes a signal voltage before writing in which a positive voltage and a negative voltage are alternately repeated a plurality of times with the common voltage as a reference. The partition wall forms a plurality of the pixel spaces,
The electrophoretic display device according to claim 4, wherein the signal voltage application unit applies the pre-writing signal voltage to a plurality of the first electrodes all at once. The electrophoretic display device according to claim 1, wherein a color of the surface of the positively charged fine particle is different from a color of the surface of the negatively charged fine particle. The electrophoretic display device according to claim 6, wherein the surface color of the positively charged fine particles is black, and the color of the surface of the negatively charged fine particles is white. The electrophoretic display device according to claim 7, wherein a diameter of the black positively charged fine particles is larger than a diameter of the white negatively charged fine particles. The electrophoretic display device according to claim 1, wherein the display unit includes a dispersion material sealed in the pixel space. The electrophoretic display device according to claim 9, wherein a dielectric constant of the dispersion material is lower than a dielectric constant of the positively charged fine particles and the negatively charged fine particles. The partition portion separates the plurality of pixels including the plurality of first electrodes, and the first electrode extends from the thin film transistor, the scanning line, and the signal line toward the second substrate. The electrophoretic display device according to claim 1, wherein the electrophoretic display device is erected so as to surround the device. An electrophoretic display device driving method for driving a display unit that displays an image by electrophoresing charged particles in a dispersion material sealed in a pixel space that is a closed space,
Applying a common voltage to the common electrode of the pixel space;
Applying a write signal voltage for displaying an image on a pixel electrode in the pixel space during a period of applying the common voltage;
During the period in which the common voltage is applied, a post-write signal voltage whose voltage changes stepwise from the write signal voltage to the holding signal voltage for maintaining the display state of the display unit is applied to the pixel electrode. Steps,
Applying a scanning signal voltage to a scanning line that turns off a preset thin film transistor having a potential different from that of the holding signal voltage after the voltage of the pixel electrode has shifted to the holding signal voltage;
A method for driving an electrophoretic display device, comprising: Before applying the write signal voltage, applying to the pixel electrode a pre-write signal voltage in which a predetermined positive voltage and a negative voltage are alternately repeated a predetermined number of times with reference to the common voltage. The method for driving an electrophoretic display device according to claim 12. A plurality of the pixel spaces are formed,
The method of driving an electrophoretic display device according to claim 13, wherein the pre-write signal voltage is applied to the plurality of pixel electrodes simultaneously.

Images